Apparatus for making sulphite liquor



Mgrch 16 1926.

F. J. BABCOCK H 17 UH Patented Mar. 16, 1926.

UNITED STATES PATENT OFFICE.

FRED J. BABCOCK, or DEXTER, new YORK, Assrenon T sTnB INs nnernnnniive,

& 'MANuFAc'runIne COMPANSLOF wamnnrown, new YORK.

AIPIEARA'IUS FOR MAKING SULPHITELIQUOR.

Application filed July 24,

To all whom it may concern: Be it known that I, FRED J. BABCOCK, a citizen of the United States, residing at Dexter, in the county of Jefferson and State of New York, have invented a new and useful Apparatus for Making Sulphite Liquor, of which the following is a spec1fication.

This invention relates to an apparatus for making sulphite liquor such as used in the manufacture of paper pulp and it is de signed more especially as a means and method for improving uponthe results obtained by the use of the ordinary well known methods, among which may be mentioned the J enssen towers, one arrangement of which has been disclosed in Patent #1,251,533. r

The invention has for one of its objects the provision of means whereby it is possible to control the ratio ofthe combined (SO, and lime) to the free SO, in the acid bisulphite liquor, thereby to prevent precipitation of lime throughout the apparatus or premature freeing of the gas.

Another object is to combine with the apparatus a means whereby thecooking acid in the recovery tank can be built up by the admission of the controllable amount of combine to meet the special conditions required of the acid bisulphite liquor.

Another object is to provide an apparatus for the purpose described which can be set up for use in connection with well known or.

" standard towers already in use.

ith the foregoing and. other objects in view the invention consists of certain novel details of construction and certain steps in the method hereinafter more fully described and pointed out in the claims, it being understood that various changes may be made withinthe scope of the claims without departing from the spirit of the invention.

In the accompanying drawing the complete apparatus has been shown partly in section and partly in elevation, portions of the main acid towers beingbroken away.

Referring to the drawing by characters of reference 1 and 2 designate towers of the usual or any preferred construction, each being provided with a grate 3 adapted to support the broken limestone indicated generally at L. A suitably driven fan has been 1924. Serial at. 727,979.

fan 4 has an outlet flue 6 provided with branches 7 and 8 which open into the lower. portions of the respective towers 1 and 2, there being valves 9' for controlling the flow of gas to these branches. Additional branches 10 extend from the flue 6 and open into the upper portion of the towers, there being a valve 11 for controlling the flow of gas.

A waterpump 12, which is adapted to be driven in any suitable manner has an inlet pipe 13, andis provided with an outlet or distributing pipe 14, one end of which opens downwardly into the tower 2. Abranch pipe 15 extends downwardly 'into the tower 1 from the pipe 14. A valve 16 is arranged within pipe 14 between its downturned end and the branch pipe15 and another valve 17 is arranged in said branch pipe 15.

A pump 18, driven in any suitable manner, has a distributing pipe 19, one end of which is downturned as at 20 so as to discharge into the tower '1. A branch pipe 21 extends downwardly from pipe 19 into the tower 2 and has a valve 22. Another valve 23 is pro vided in pipe 19 between the downturned end 20 and the branch 21.

Each of the towers has a pipe 24 extending upwardly .therefrom' and constituting a vent for carbon dioxide; I

Tank 1 has an outlet pipe 25 for acid in the tower and this pipe communicates with a pipe 26 extending to the inlet of the acid pump 18. Another outlet. pipe 27 extends from the pump portion of the tower 2 and communicates through a pipe 28 with pipe 26. A connecting pipe 29 communicates with the two outlet pipes 25 and 27 and valves 30 are provided for controlling communication between the pipes 25 and 27 t0 the pipes 26, 28 and 29. Supplemental outlet pipes 31 are extended from the lower portions of the towers and are provided with valves 32. These pipes open into the connecting pipe 29.

The parts thus far described are substantially the same as those heretofore used in the art of making sulphite liquor. It has been found, however, that it has been impossible to maintain the acid liquor in the recovery tank of a standard quality under all conditions and it is for this reason that a supplemental means has been devised for building up the acid liquor in the recovery tank to meet the conditions.

The improvments constituting the present invention include a small supplemental tower 39, the grate 40 of which is adapted to support limestone L. A branch pipe 41 is extended to the supply pipe 5 from the top of the tower 39 and another pipe 42 is extended downwardly into the top of tower 39 from a circulating pump 43 which is fed through a valved pipe 44 from the bottom of the recovery tank 38. An outflow pipe 45 extends from the bottom portion of the tower 39 and communicates with branch pipes 50 which discharge into the respective tanks 36 and 38. Each of these branch pipes has a valve 51.

It is believed that the method followed in the manufacture of sulphite liquor will be readily understood by those skilled in the art. After the limestone has been placed in the towers 1 and 2 the gas fan is set in motion so as to cause a circulation of gas through the towers as indicated by arrows so that the gas will pass successively upwardly through the tower 1 and thence upwardly through tower 2. Water pump 12 is operated and as valve 17 is closed and valve 16 open, the water will fiow from the pump into the upper end of tower 2 where it will be sprayed onto the limestone. and combine therewith and with the gas to produce a weak acid liquor. As pipe 27 is in communication with pipe 28. the weak acid liquor thus produced will flow to the pump 18 which will elevate the acid liquor through pipe 19. Valve22 is closed and valve 23 is open. Thus the weak acid liquor will be di rected downwardly into the tower 1 where the strong raw acid liquor is produced. This strong acid liquor will flow downwardly through pipe 25 to pipe 29 and as this pipe is in communication with the pipe 28, said acid liquor will flow into the trap 34:, thence to the storage tank 36, and into the recovery tank 38. Relief gas from the digester is preferably admitted to the recovery tank through pipe 52.

For the purpose of maintaining thestandaid of the acid liquor in the recovery tank the supplemental tower 39 is used and when the acid liquor is to be built up the pump 43 is set in motion and valve 44: opened. Thus a portion of the acid liquor in the tank is withdrawn and is sprayed downwardly onto the limestone in the tower 39. The strengthened acid liquor thus produced is then returned to tank 38 through the pipes 4-5 and 50, one of the valves 51 being closed at this time. The amount of strengthened acid liquor thus introduced in the tank 33 depends altogether upon the extent to which the acid liquor must be built up for use, but it will be obvious that the building up operation can be continued as long as desired and when the proper strength has been obtained in the recovery tank, the valve 14 can be closed and the operation of the pump 43 discontinued.

It will of course be understood that the flow of gas and liquor described heretofore J1 be reversed simply by properly manipulating the valves in the several pipes and the strengthened acid liquor produced in the supplemental tower 39 can, if desired, bt directed into the tank 36 instead of the tank 38 or can be directed into both of the tanks as preferred.

lVhat is claimed is In an acid liquor tower system the combination with separate reversible limestone towers and a tank for receiving acid liquor from either of the towers, of means for building up the acid liquor in the tank, said. means including a supplemental tank in communication with the first named tank for receiving relief gas, a supplemental limestone tower, means for directing gas to said supplemental limestone tower, and means for recirculating liquor through said supplemental tank and said supplemental tower while gas is being supplied to the tower.

In testimony that I claim the foregoing as my own, I have hereto aflixed my signature.

FRED J. BABCOCK. 

